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彩电中频校准器
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作者 赵平来 《现代通信》 1997年第2期22-22,共1页
彩电中频校准器赵平来在彩电维修中,公共通道的同步检波、AFT外接LC谐振回路(俗称同步检波线圈和AFT线圈,下称LC回路)失谐率较高,由其引起的故障现象也多种多样,如自动搜索不存台、存台不准、声像不兼顾、彩色不稳、无... 彩电中频校准器赵平来在彩电维修中,公共通道的同步检波、AFT外接LC谐振回路(俗称同步检波线圈和AFT线圈,下称LC回路)失谐率较高,由其引起的故障现象也多种多样,如自动搜索不存台、存台不准、声像不兼顾、彩色不稳、无图像等等。若在没有仪器的情况下进行... 展开更多
关键词 彩电 频校准器 维修
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A Fractional-N CMOS DPLL with Self-Calibration
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作者 刘素娟 杨维明 +2 位作者 陈建新 蔡黎明 徐东升 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2005年第11期2085-2091,共7页
A digital phase-locked loop (DPLL) based on a new digital phase-frequency detector is presented. The self-calibration technique is employed to acquire wide lock range,low jitter, and fast acquisition. The DPLL works... A digital phase-locked loop (DPLL) based on a new digital phase-frequency detector is presented. The self-calibration technique is employed to acquire wide lock range,low jitter, and fast acquisition. The DPLL works from 60 to 600MHz at a supply voltage of 1.8V. It also features a fraetional-N synthesizer with digital 2nd-order sigma-delta noise shaping, which can achieve a short lock time,a high frequency resolution,and an improved phase-noise spectrum. The DPLL has been implemented in SMIC 0. 18μm 1.8V 1P6M CMOS technology. The peak-to-peak jitter is less than 0. 8% of the output clock period and the lock time is less than 150 times of the reference clock period after the pre-divider. 展开更多
关键词 digital phase-locked loop phase-frequency detector SELF-CALIBRATION voltage controlled oscillator FRACTIONAL-N
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A Σ-Δ Fractional-N PLL Frequency Synthesizer with AFC for SRD Applications 被引量:1
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作者 章华江 胡康敏 洪志良 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2008年第7期1298-1304,共7页
A fractional-N frequency synthesizer for 433/868MHz SRD applications is implemented in a 0.3μm CMOS process. A wide-band VCO and an AFC are used to cover the desired bands. A 3bit third order sigma-delta modulator is... A fractional-N frequency synthesizer for 433/868MHz SRD applications is implemented in a 0.3μm CMOS process. A wide-band VCO and an AFC are used to cover the desired bands. A 3bit third order sigma-delta modulator is adopted to reduce the out-band phase noise. The measurements show a VCO tuning range from 1.31 to 1.88GHz with AFC working correctly,an out-band phase noise of -139dBc/Hz at 3MHz offset frequency, and a fractional spur of less than - 60dBc. The chip area is 1.5mm × 1.2mm and the total current dissipation including LO buffers is 19mA from a single 3.0V supply voltage. 展开更多
关键词 short range device phase locked loop adaptive frequency calibration frequency synthesizer SIGMA-DELTA
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A 5-GHz frequency synthesizer with constant bandwidth for low IF ZigBee transceiver applications
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作者 姜亚伟 李智群 +1 位作者 舒海涌 侯凝冰 《Journal of Southeast University(English Edition)》 EI CAS 2010年第1期6-10,共5页
A fully integrated integer-N frequency synthesizer is implemented.The synthesizer is designed for low intermediate frequency (IF)ZigBee transceiver applications.Techniques used to make the loop bandwidth constant ac... A fully integrated integer-N frequency synthesizer is implemented.The synthesizer is designed for low intermediate frequency (IF)ZigBee transceiver applications.Techniques used to make the loop bandwidth constant across the whole output frequency range of the voltage controlled oscillator(VCO)are adopted to maintain phase noise optimization and loop stability.In-phase and quadrature(IQ)signals are generated by a 1/2 frequency divider at the output of the VCO.The synthesizer is fabricated in 0.18 μm radio frequency(RF) complementary metal oxide semiconductor transistor (CMOS)technology.The chip area is 1.7 mm2.The synthesizer is measured on wafer.It consumes totally 28.8 mW excluding output buffers from a supply voltage of 1.8 V.The measured phase noise is -110 and -122 dBc/Hz at the offset of 1 and 3 MHz from a 2.405 GHz carrier,respectively.The measured reference spur at a 2 MHz offset from a 2.405 GHz carrier is-48.2 dBc.The measured setting time of the synthesizer is about 160 μs. 展开更多
关键词 phase-locked loop phase noise auto frequency calibration ZIGBEE voltage controlled oscillator
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Measurement of 3db Bandwidth of Laser Diode Chips
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作者 徐遥 王圩 王子宇 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2003年第8期794-797,共4页
An accurate technique for measuring the frequency response of semiconductor laser diode chips is proposed and experimentally demonstrated.The effects of test jig parasites can be completely removed in the measurement ... An accurate technique for measuring the frequency response of semiconductor laser diode chips is proposed and experimentally demonstrated.The effects of test jig parasites can be completely removed in the measurement by a new calibration method.In theory,the measuring range of the measurement system is only determined by the measuring range of the instruments network analyzer and photo detector.Diodes' bandwidth of 7 5GHz and 10GHz is measured.The results reveal that the method is feasible and comparing with other method,it is more precise and easier to use. 展开更多
关键词 bandwidth measurement CALIBRATION frequency response semiconductor laser diode chips
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